This study will evaluate the carcinogenicity and chronic toxicity of D & C Yellow #11 by administering the compound in utero to F344 rats. This will be accomplished by administering D & C Yellow #11 in the diet at concentrations of 0,500, 1700, or 5000 ppm to groups of male and female F344 rats. After 70 days of chemical exposure these F(o) parents will be mated but will continue to receive diets containing D & C Yellow #11 during gestation and lactation. F(1) weanlings from the respective chemically exposed or control groups will be randomized into treatment groups and continue to receive diets containing D & C Yellow #11, at the concentration appropriate for their group, throughout their life time. After 52 weeks of exposure up to 10 animals per group will be necropsied, all tissues saved and processed for histopathology. In addition, at the time of sacrifice, blood will be drawn from each animal and a battery of hematological parameters evaluated. After 103 weeks of exposure to D & C Yellow #11 containing diets, all surviving animals will be necropsied, all tissues saved and processed for histopathology, and histopathologic evaluation conducted.